HD 3850 AGP poor opengl performance

Joined
Dec 15, 2008
Messages
10
I recently got a sapphire ATI radeon HD 3850 AGP and it runs many games really well

I can even max out crysis warhead with no lag and hold 20-25FPS at 1440x900

But my problems start with games using opengl, mainly second life

I get 6-15FPS and it is very laggy.
And if I try to turn or move, the game goes down to 1-3 FPS and hangs and stutters as the scene is rendered (probably due to it making almost no use of the video memory (I have noticed this with many opengl apps)

When I checked using rivatner, the GPU usage of the card was at 30% and the game was only using 5.44MB memory


With my old geforce 6800, the game was able to use all of the 256mb memory
And my average framerate with it was 25-30FPS


I dualboot multiple copies of windows xp, and I recently installed another XP to make sure it wasn’t a problem with moving from nvidia to ATI

Still had the same problem

Why does the card refuse to use more than 5.44MB video memory with many open gl apps

My system specs:

Motherboard:
CPU Type DualCore AMD Opteron 170, 2717 MHz (9.5 x 286)
Motherboard Name Asus A8V (5 PCI, 1 AGP, 4 DDR DIMM, Audio, Gigabit LAN)
Motherboard Chipset VIA K8T800Pro, AMD Hammer
System Memory 2048 MB (PC3200 DDR SDRAM)
DIMM1: G Skill NS 1 GB PC3200 DDR SDRAM (2.5-3-3-6 @ 200 MHz)
DIMM2: G Skill NS 1 GB PC3200 DDR SDRAM (2.5-3-3-6 @ 200 MHz)

Display:
Video Adapter ATI Radeon HD 3800 Series (512 MB)


Screenshot of sl and riva tuner http://img410.imageshack.us/img410/4189/39558766kj8.jpg



I will be testing more opengl games but so far it seems that they refuse to use texture memory

so games can run ok if your not moving and just looking at 1 thing but once you move or turn the cam, the lack of use of the texture memory causes extreme lag, like it will freeze for like 2 -5 seconds in some cases while it loads the view

it seems to not use full gpu usage due to probably a bottle neck from not using the videocards texture memory.

just tried cinebench open gl test, it got aroud 43 FPS, low cpu usage and low GPU usage, barely any texture memory usage
 
I just tried another app for opengl info on the card and I found something strange which may explain the problem

http://www.ozone3d.net/gpu_caps_viewer/

my card shows this

88472121hj3.jpg


it shows 0MB opengl texture memory

while for the main card info it shows me having 512MB memory, just 0 for opengl

on my old card, it detected 128
 
I have the same thing 0 texture array layers and 0 texture buffer size.. no clue what it means..
 
basically means opengl games wont use the videocards texture memory so textures get pushed into system memory and virtual memory, which leads to really bad performance on texture intensive games because you are no longer using the super fast 60+GB/s memory in the card, your stuck using the slower system memory and even slower virtual memory

which is why my geforce 6800 didn't lag with second life or many other opengl games while my new 3850 which is many times faster and runs d3d games very fast is unable to handle easy to run opengl games

much of the system memory bandwidth is needed to running the actual game, there just isn't enough for textures. if it is a driver problem I hope amd/ati fixes it
 
have to admit I miss my 6800pro sigh, it lives in arizona now.

are there any opengl games still around? thought d3d games pretty much took over?
 
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